By Dan Balz
The pattern in Campaign 2008 is that nothing lasts; nothing has a shelf life of more than half a day. Cable and the internet simply churn information too quickly. In this age of the continuous news cycle, the new pushes out the old regardless of significance or importance.

In that context, it is worth returning to Barack Obama's speech on race and the Rev. Jeremiah Wright, a speech and a subject not likely to disappear any time soon. The question is what will last longer -- Obama's eloquent words about racial divisions and reconciliation or questions about his relationship with a man whose words have shocked the country.

In so many ways, Obama's speech was remarkable: ambitious, lofty, gritty, honest and unnerving. In tone and substance, and in the challenge he laid down to the country about the need somehow to move beyond the racial stalemate, it was the kind of speech Americans should expect of a presidential candidate or a president.

Obama was uniquely equipped to give this speech. As the child of a mixed race couple -- a black Kenyan father who abandoned his wife and young son and a white American mother who raised him with the help of her Kansas parents -- he has struggled with this topic his entire life. His emergence in this presidential campaign is in no small measure the result of successfully making that journey.

Obama has lived in black and white throughout his life and it seemed as if everything he had seen and absorbed and internalized about divisions between the races went into what he said on Tuesday at the National Constitution Center in Philadelphia. As he has shown at other moments in the campaign, his gifts of intelligence, of reasoning and of language are considerable. Both what he said about race and the way in which he said it showed political and intellectual heft. Which is why the address has drawn considerable praise, as a model of what political rhetoric should seek to attain.

But at heart, this was a speech designed for a political purpose, and Obama may have received more credit than he deserves for taking up the subject. Sitting in the small auditorium on Tuesday, watching Obama speak in what seemed like deliberately flat and unemotional tones, there was no way to think about the address as other than a political rescue mission. And on that there is no simple verdict, only lingering questions.

Obama said that the politically easy thing would be to hope that the firestorm triggered by video excerpts from Wright's sermons would somehow fade away. Instead, he said, the Wright controversy provided the pretext for -- even demanded! -- a more honest confrontation of the racial divisions that persist and a more open-minded understanding by whites and blacks of why bitterness and anger on each side of that divide exists.

Obama obviously knew better that to pretend that the ugly controversy would somehow disappear. Wright in fact had created the most serious crisis Obama has faced in this campaign and no amount of wishing would change that fact. The candidate rightly understood the threat to his candidacy and immediately told his advisers that he wanted to deliver a major speech on the subject. By enlarging the discussion, he hoped to defuse what was most dangerous to his political aspirations -- his long association with a prominent figure who has said things many Americans -- white and black -- find repulsive.

Democratic strategists see the dangers ahead for Obama. While not lethal to his hopes of winning either the Democratic nomination or the presidency, they say, the damage could be lasting. "This has tarnished Obama's image, though certainly not in a fatal way, and we will see it used by the GOP repeatedly if he is the nominee," one strategist wrote in an e-mail Wednesday. "At the end of the day, I believe whoever the Democratic nominee is will win, but those who think that, if Obama is the nominee, he won't have Clinton-like negatives by Election Day are naive. This whole episode underlines that point."

Another Democratic strategist offered this thought late Tuesday. The speech was one of the best ever given on the topic of race in America, he noted, but the controversy over Wright will dog Obama in a general election and could hurt him in the nomination battle, depending on how delegates react to it and reconsider whether Obama or Hillary Clinton would be the stronger nominee against John McCain.

Still another simply noted that Obama and his campaign team will need to return to this problem, as good as the speech may have been. In other words, it's not going away.

What can't be known at this point is how the episode is resonating around the country among independents or what were once called Reagan Democrats. Has Obama reached them in a way that inspires their confidence that he is perhaps uniquely equipped not just to start a conversation but to lead the country to a new, if still imperfect, place in racial relations? Or has he simply raised doubts among them about who he is?

What made Tuesday's speech so difficult for Obama was the challenge of trying to speak through the anger -- the anger of Wright's words and the anger among those now first exposed to them -- and move the country and the conversation to a different level. That was doubly difficult because his relationship with Wright was so personal that trying to explain Wright was not enough; he also had to explain something about himself. Rhetorically he accomplished it, but it is not certain by any means that politically he did the same.

Obama's hope is that what is lasting from this experience is a renewed effort for the country to speak with honesty and good will about the state of race relations. History suggests the country may quickly tire of taking on something that arduous. The danger is that what will last are the images of his Chicago pastor, edited and reedited into television ads, YouTube videos and an endless stream of e-mails delivered quietly into the computers of millions of Americans. That would be good neither for Obama, nor for the goals he talked about on Tuesday.